Choosing a Cheap Small PC for KVM Virtualization

Selecting the right small PC for running KVM (Kernel-based Virtual Machine) guests requires careful consideration of several factors, including processing power, memory, storage, and overall system compatibility. This guide provides a comprehensive overview of suitable options, focusing on both pre-built mini PCs and custom build possibilities, while emphasizing the key hardware requirements for effective virtualization.

Essential Hardware Requirements for KVM

Before diving into specific models, it's crucial to understand the core hardware requirements for running KVM guests efficiently:

1. CPU with Virtualization Support

   The central processing unit (CPU) is the most critical component. It must support hardware virtualization extensions, which are essential for KVM to function correctly. These extensions are known as:

   • Intel VT-x (with VT-d for I/O virtualization): Found in most modern Intel processors.
   • AMD-V (with AMD-Vi for I/O virtualization): Found in most modern AMD processors.

   Ensure that the CPU you choose has these features enabled in the BIOS/UEFI settings. A multi-core processor is highly recommended, as each virtual machine (VM) will benefit from having dedicated cores or threads. Quad-core or higher processors are ideal for running multiple VMs simultaneously.

2. Sufficient RAM

   Random Access Memory (RAM) is vital for running multiple VMs concurrently. Each VM requires its own allocation of RAM, so the total amount of RAM in your system should be sufficient to handle the host operating system and all the guest VMs. A minimum of 8GB of RAM is recommended, but 16GB or more is highly advisable, especially if you plan to run multiple or resource-intensive VMs. For optimal performance, consider 32GB or more if your budget allows.

3. Fast Storage

   Storage speed significantly impacts the performance of VMs. Solid-state drives (SSDs) are highly recommended over traditional hard disk drives (HDDs) due to their much faster read and write speeds. NVMe SSDs, which use the PCIe interface, offer even better performance than SATA SSDs. A minimum of 256GB of storage is recommended, but 512GB or 1TB is preferable if you plan to host multiple VMs or store large amounts of data within the VMs. Consider the number of VMs you plan to run and their storage needs when selecting storage capacity.

4. Networking

   A reliable network connection is essential, especially if your VMs need to communicate with each other or with the external network. A Gigabit Ethernet port is highly recommended for faster data transfer. Dual NICs (Network Interface Cards) can be beneficial if you need to isolate network traffic between the host and guest VMs, or if you plan to use network bridging or routing.

5. Cooling and Power

   Small PCs can generate significant heat, especially when running multiple VMs. Ensure that the system has adequate cooling to prevent overheating and maintain performance. Also, consider the power consumption of the system, especially if you plan to run it continuously. Energy-efficient models can save you money in the long run. A sufficient power supply is crucial, especially if you are building your own system.

Recommended Small PC Options

Here are some specific small PC options that are well-suited for running KVM guests, categorized by type:

Intel NUC Mini PCs

Intel NUCs (Next Unit of Computing) are compact, powerful, and generally reliable. They are a popular choice for virtualization due to their small size and decent performance.

• Intel NUC 11 Performance (Panther Canyon)

  • CPU: Intel Core i5-1135G7 (or similar)
  • RAM: Supports up to 64GB DDR4
  • Storage: M.2 NVMe SSD slot
  • Pros: Compact, reliable, good performance for most virtualization tasks.
  • Cons: Can be more expensive than other mini PC options.

• Intel NUC 10 Performance (Frost Canyon)

  • CPU: Intel Core i3-10110U or i5 variants
  • Pros: More affordable, still offers decent performance for light to medium workloads.

• Intel NUC 10th Generation (NUC10i3FNH)

  • CPU: Intel Core i3-10110U (2 cores, 4 threads, up to 4.1 GHz, with VT-x and VT-d support)
  • RAM: Upgradeable to 32GB DDR4
  • Storage: M.2 SSD slot (256GB or higher recommended)

AMD-Based Mini PCs

AMD-based mini PCs offer excellent multi-core performance and are often more cost-effective than their Intel counterparts.

• ASUS PN Series (e.g., ASUS PN50)

  • CPU: AMD Ryzen 5 4500U (or similar)
  • RAM: Typically up to 64GB
  • Storage: M.2 NVMe SSD and 2.5-inch HDD/SSD
  • Pros: Good multi-core performance, cost-effective.

• Minisforum UM790 Pro

  • CPU: AMD Ryzen 9 7940HS
  • GPU: AMD Radeon 780M
  • RAM: 32GB DDR5
  • Storage: Dual M.2 PCIe 4.0 SSD slots
  • Pros: Powerful, suitable for resource-intensive VMs.
  • Cons: Not the cheapest option.

• Minisforum Mercury EM780

  • CPU: AMD Ryzen 7 7840U
  • GPU: AMD Radeon 780M
  • RAM: 32GB
  • Pros: Ultra-small form factor, fast performance.

• ASUS PN50

  • CPU: AMD Ryzen 3 4300U (4 cores, 4 threads, up to 3.7 GHz, with AMD-V support)
  • RAM: Upgradeable to 32GB DDR4
  • Storage: M.2 SSD slot (256GB or higher recommended)

• Zotac ZBOX

  • Various models with AMD Ryzen or Intel CPUs.
  • Pros: Versatile and customizable configurations.

Other Mini PC Options

• Beelink U59

  • Pros: Affordable, dual HDMI outputs, dual gigabit LAN ports.
  • Suitable for embedded use and remote access.

• Gigabyte Brix

  • Model: Gigabyte Brix GB-BLCE-4105
  • CPU: Intel Celeron J4105 (4 cores, 4 threads, up to 2.5 GHz, with VT-x support)
  • RAM: Upgradeable to 8GB DDR4
  • Storage: M.2 SSD slot (128GB or higher recommended)

• Asus Chromebox

  • Specs: Recent models feature Intel processors (Celeron and Core series), 4GB+ RAM.
  • Pros: Compact size and very energy-efficient.
  • Cons: May require a bit more setup and may not support certain Linux distributions well.

Refurbished or Used Small PCs

Purchasing refurbished or used small PCs can be a cost-effective way to get a capable machine for running KVM guests.

• HP ProDesk or Dell OptiPlex Mini Desktops

  • Examples: HP ProDesk 400 G6 Mini, Dell OptiPlex 3080 Micro
  • CPUs: Intel Core i5 or i7 options
  • Pros: Enterprise-grade reliability, often available at lower prices.

• Used Enterprise PCs

  • Look for models from Dell, HP, or Lenovo.
  • Pros: Cost-effective, often well-built.
  • Cons: May have limited warranty and potential wear and tear.

Custom Mini-ITX Builds

If you're comfortable building your own system, a custom Mini-ITX build can offer excellent performance and flexibility.

• Components

  • Motherboard: Mini-ITX motherboard
  • CPU: AMD Ryzen 3/5 or Intel i3/i5
  • RAM: 16GB or more
  • Storage: SSD (NVMe recommended)
  • Case: Small form factor case (e.g., Cooler Master NR200, SilverStone SG series)

• Pros

  • Customizability, upgrade options, decent power for multiple VMs.

• Cons

  • Requires building and may be more expensive than pre-built options.

Raspberry Pi 4 (For Light Use)

The Raspberry Pi 4 is a very affordable option, but it is best suited for lightweight VMs or development/testing environments.

• CPU: Quad-core ARM Cortex-A72
• RAM: Up to 8GB
• Storage: microSD or external SSD via USB 3.0
• Pros: Extremely affordable and compact.
• Cons: Limited performance for heavier virtualization tasks.

Additional Considerations

• Operating System

  • Ensure the PC supports a compatible OS for running KVM, typically a recent version of Linux (like Ubuntu, CentOS, or Fedora).

• Software Optimization

  • Use lightweight Linux distributions optimized for virtualization to maximize performance.

• Expandability

  • Consider future needs; a machine that allows for RAM upgrades or additional storage may be beneficial.

• Budget

  • Set a budget that considers both initial purchase and potential upgrades.

• Cooling and Ventilation

  • Especially important in compact builds to maintain performance and longevity.

• Network Connectivity

  • Gigabit Ethernet is preferable for faster data transfer between host and guests.

• Power Consumption

  • If you're running this machine continuously, consider its power consumption; energy-efficient models can save you money in the long run.

Conclusion

Selecting a cheap small PC for running KVM guests involves balancing cost with performance and future scalability. Intel NUCs and AMD-based mini PCs are excellent starting points due to their compact size and reliable performance. For more budget-conscious options, refurbished desktops or building a mini-ITX system can provide great value. Always ensure the chosen hardware supports the necessary virtualization features and meets the performance demands of your intended VM workloads. By carefully considering the factors outlined above, you can find a small PC that meets your needs without breaking the bank.